2-Thiophenecarboxylic acid, 5-chloro-

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 Okt - 8 Nov 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

HPLC-UV/VIS

Details on sampling:

- Sampling method: Aliquots of the samples from the biological test were directly analyzed by HPLC and UV/VIS-detection (range of the injection volume: 1-100 µL, depending on the expected concentration).
- Sample storage conditions before analysis: Routinely, the samples are analyzed immediately. Only in exceptional cases, they are stored overnight deeply frozen and protected from light.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: To produce the test concentration, 105.2 mg of the test substance were added to 1 L of dilution water, treated for 1 hour in an ultrasonic bath and then stirred for 24 h on a magnetic stirrer.
- Controls: 1 control

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: parthenogenetic females
- Age at study initiation: 0-24 h
- Stage and instar at study initiation: Neonates
- Method of breeding: well-established test culture
- Source: Bundesgesundheitsamt Berlin
- Feeding during test: no

ACCLIMATION
- Acclimation period: The culture water (so called 'M4 medium') is partly renewed once a week.
- Type and amount of food: The Daphnia are exclusively fed with unicellular green algae (Desmodesmus subspicatus) 'ad libitum'

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS
- The neonates are separated from their parent Daphnia by filtration prior to the acute test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

15.7°dH (=280.25 mg/L CaCO3)

Test temperature:

20.4 to 20.5 °C

pH:

7.9 to 8.3

Dissolved oxygen:

8.6 mg/L

Nominal and measured concentrations:

100 mg/L (nominal concentration)

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL glass beakers
- Volume of solution: 20 mL of test medium
- Aeration: no
- No. of organisms per vessel: 10 neonates
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water (M4-medium)
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Photoperiod: 16 h light, 8 h dark
- Light intensity: < 1000 lux

EFFECT PARAMETERS MEASURED
- Immobilization rates are recorded at 24-hour intervals

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Calculated on the basis of EC0 ≥ 100 mg/L (nominal concentration).

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Immobilisation of control: 0%
- Immobilisation with test substance: 0%

Chemical analysis of the test substance

Chemical analysis	0 h	48 h
HPLC replicates [mg/L]	105.918/ 103.977	98.648/ 98.823
HPLC mean values [mg/L]	104.95	98.74

Chemical analysis of the control 

Chemical analysis	0 h	48 h
HPLC replicates [mg/L]	<0.064/ <0.064	<0.064/ <0.064
HPLC mean values [mg/L]	<0.064	<0.064

Validity criteria for the measurement of the daphnia toxicity

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
In the control, including the solubilising agent, not more than 10 % of the daphnids should have been immobilized. (Not more than 10 % of the control daphnids should show immobilisation or other signs of disease or stress, for example, discoloration or unusual behaviour such as trapping at surface of water)	Immobilization of control: 0%	Yes
The dissolved oxygen concentration at the end of the test should be >/= 3 mg/L in control and test vessels.	Dissolved oxygen concentration was 8.6 mg/L in control and test vessels.	Yes
The concentration of the test item shall be maintained to within 80% of the initial concentration throughout the study. The maintenance of concentration is proved by analytical measurements	Recovery rates correspond to 104.9% of nominal value at 0 hours and to 98.7% of nominal value at 48 hours.	Yes
A limit test may be performed at 100 mg/L of the test substance in order to demonstrate that the EC50 is greater than this concentration. The limit test should be performed using 20 daphnids, with the same number in the control. If the percentage of immobilisation exceeds 10% at the end of the test, a full study chould be conducted.	Within the limit test, 20 daphnids were used for the test concentration of 100 mg/L (2 replicates and 10 daphnia per test vessel) and 20 daphnids for the control (2 replicates and 10 daphnia per test vessel). No immobilization of daphnids was observed within the test.	Yes

 

Validity criteria fulfilled:

yes

Remarks:

See 'Any other information on results incl. tables'.

Conclusions:

EC50 (48 h) >100 mg/L

Executive summary:

The study was performed to assess the acute toxicity of the test substance to Daphnia magna under static conditions. The study was conducted in accordance with 92/69/EEC Part C, Method 2 'Acute toxicity for Daphnia' which is in most parts equivalent to the OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test and Reproduction Test, Part I- The 24h EC50 Acute Immobilisation Test'. The Daphnia were exposed to a limit test concentration of nominally 100 mg/L of the test substance dissolved in water. Auxiliaries used to prepare the test media were an ultrasonic bath and a magenetic stirrer. Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. The following values were determined: EC0>/=100 mg/L nominal concentration (48 h). Recovery rates correspond to 104.9% of nominal value at 0 hours and to 98.7% of nominal value at 48 hours. The EC50 was derived from the raw data since no effects were observed.

Description of key information

A study was performed to assess the acute toxicity of the test substance to Daphnia magna under static conditions. The study was conducted in accordance with 92/69/EEC Part C, Method 2 'Acute toxicity for Daphnia' which is in most parts equivalent to the OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test and Reproduction Test, Part I- The 24 h EC50 Acute Immobilisation Test'. The Daphnia were exposed to a limit test concentration of nominally 100 mg/L of the test substance dissolved in water. Auxiliaries used to prepare the test media were an ultrasonic bath and a magenetic stirrer. Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. The following values were determined: EC0 ≥ 100 mg/L nominal concentration (48 h). Recovery rates correspond to 104.9% of nominal value at 0 hours and to 98.7% of nominal value at 48 hours. The EC50 was derived from the raw data since no effects were observed.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Remarks:

Calculated on the basis of EC0 ≥ 100 mg/L (nominal concentration).

Effect concentration:

> 100 mg/L